A past puzzle — fully playable. 4 attempts, hints on wrong guesses.
stdle-97.js
1constobj=JSON.parse('{"x":1}');
2constclone=structuredClone(obj);
3console.log(clone.x,obj===clone);
Quirks
Answer & explanation
Console output
1 false
Why
structuredClone returns a new object that is a deep copy of the input, so the data is duplicated (clone.x is 1) but it is a different reference. Comparing with === checks identity, not contents, so obj === clone is false. Equal data does not imply the same object.